I’m scared to tell him, but I feel that he should know

I can’t stop thinking about him. I crushed so hard on him in high school and no matter what, I cannot forget about him. He radiated absolute joy, and no matter what silly or stupid thing I talked about with him, it felt so good. I’m terrified and so saddened that this has happened, or that these suppressed feelings may continue to eat at me. I can’t keep this down, as it always comes back up and I am in tears again. Perhaps it’s stupid, absolutely meaningless and totally irrational, but I can’t deny it, and the fact that I haven’t told him or anyone just leaves me with so much regret and sadness that it actually starts to hurt and make me physically and mentally sick. I don’t want to hurt him or scare him but I don’t want to keep crying and feel the need to die from this loneliness. I just want to know that he’s happy so badly, and I would of course like to be there for him as much as I could to the best of my abilities, but if he rejects me or is terrified, I just don’t know, but I think I want to know. I’ve never felt so hurt by someone or something, I’m just scared of hurting him by intruding on his happiness and that of others in his life, but not being able to try is a pain that I don’t wish on anyone, especially not him.